Pin tumbler assembly



United States Patent @fificc Patented J....15,1%3

3,073,146 PIN TUMBLER ASSEMBLY George P. Patriquin, Gardener, Mass,assiguor to Independent Lock Company, Fitchburg, Mass., at corporationof Massachusetts Filed Nov. 4, 1960, Ser. No. 67,397 7 Claims. (Cl.70-383) This invention relates to a method for providing, and theresultant improved lock assembly, and more particularly to a pin tumblerlock assembly.

Still more particularly, this invention relates to a tumbler lockassembly having a factory pin tumbler combination which renders the lockoperable by a first key, said lock including novel means wherebyoperation by a specially designed second key will disable subsequentoperation by the first mentioned key.

In the construction of new homes, apartment houses, office buildings,and the like, it is desirable to provide the workers with means forlocking the individual units on which they are working in order tosafeguard tools, construction materials and the like, which arenecessarily left on the job. After construction work has been completed,however, it is necessary to assure the security of the tenant or ownerthat the combination of the locks previously employed be changed, sothat holders of keys during the construction period are not able, aftercompletion of the job, to reenter the premises through the use of theseconstruction keys.

In the past, changing of the pin tumbler combination has requiredremoval of the lock from the door, disassembly of the tumbler mechanism,and substitution of new driver and follower pins for the pins originallyprovided-in short, an operation requiring the skills of an experiencedlocksmith. Accordingly, it is an object of the present invention toprovide a pin tumbler mechanism for use in door locks, and the like, thecombination of said mechanism being adapted to be changed withoutdisassembly of the door lock mechanism or the pin tumbler unit.

A further object of this invention is to provide a pin tumbler assembly,the combination of which assembly may be changed through the use of aspecially prepared key.

A further object of this invention is to provide a pin tumbler assembly,the combination of which is changeable in the manner aforessaid by aspecial change key, the construction of the tumbler mechanism being suchthat one change key may be effective to change the combinations of aplurality of tumbler mechanism, all of which mechanisms may havedifferent combinations after such change.

Still a further object of this invention is to provide a pin tumblermechanism as aforesaid, wherein the change key may, if desired, beadapted for use as a master key.

A still further object of this invention is to provide a pin tumblermechanism having a frangible follower pin in at least one tumblerthereof, said mechanism being operable by a key having one combinationprior to fracture of said frangible pin, and being operative to that keyafter fracture of said follower pin.

The invention also has for its object a method of quickly andinexpensively converting a pin tumbler lock from one combination toanother whereby only a predeterminedly bitted key will operate the keyactuating mechanism and the removal of the pin'tumbler assembly tochange the combination for key actuation is avoided.

To attain these objects and such further objects as may appear herein orbe hereinafter pointed out, reference is made to the accompanyingdrawings, forming a part hereof in which:

FIGURE 1 is a vertical section through a pin tumbler assembly inaccordance with the invention;

FIGURE 2 is a magnified fragmentary section illustrating the positionsof the parts in the conversion or change tumbler with a construction ortemporary key in position in the keyway;

'FIGURE 3 is a section simlar to the section of FIG- URE 2 with theconversion or change key positioned in the keyway;

FIGURE 4 is a view similar to the view of FIGURE 2 showing the changedcombination; and

FIGURE 5 is a view similar to the view of FIGURE 2 showing the ownerskey in position within the keyway of the plug.

In accordance with the invention, a tumbler casing 10 is provided with aplug 11 rotatably mounted within main bore 12 of the casing. An annularflange 13 on the outer face of plug 11 is seated within annular shoulder14 formed in the face plate 15 carried by the casing 10, therebylimiting the inward relative movement of the plug with respect to thecasing 10. Movement of the plug 11 outwardly of the casing 10 isprevented by split spring washer 16 seated in annular groove 17 of theplug 11, said washer bearing against end wall 18 of the casing. The plug11 is provided in the usual manner with a longitudinally extendingkeyway 19.

The casing 10 and plug 11 are provided in the usual manner with rows ofparallel cross bores or holes 20, 21, respectively, for the driversprings, driver pins and follower pins. It will be understood that thecross bores 21 by rotation of the plug 11 will be brought into registrywith the bores 21 in the casing. The bores 20 and 21 are charged withpaired driver and follower pins 22, 23, respectively, and with driversprings 24 bearing, at their upper ends 25, against the cap plate 30,and at their lower ends 26, against the upper or outer ends of driverpins 22. Springs 24 act in the usual manner normally to project thefollower pins fully and the driver pins partly into the cross bores 21of the plug, thereby causing the driver pins 22 to straddle the shear orparting line AA, thereby preventing the rotation of the plug 11 withrespect to the casing 10 without the use of a suitable key.

The structure thus far described is conventional in nature, and theinvention herein is concerned with the cross borings 20a, 21a, of thecasing and plug, respectively, and the associated novel pins or tumblerscharged therein, as well as the novel key mechanisms hereinafterdescribed, it being understood that while one such assembly is shown, itmay be embodied in as many of the borings as it may be desired to alterby the present invention.

In accordance with the illustrated embodiment, cross bore 20a isenlarged as compared with cross bores 20. The bore 20a is charged with adriver pin 22a and an auxiliary driver pin 23b, the pins being urgedradially inwardly toward the axis of the main bore 12 by a driver pinspring 24a, having its upper end 2511 biased against the cap 30, and itslower end 26a biased against driver pin 22a. The bore 21a of the plug 11is, in contrast to the bores 21, optionally but preferably drilledentirely through the plug 11. In addition, the bore 21a includes anenlarged counter-bored entering portion 21b, defining with the remainderof said bore an annular shoulder 210. A frangible follower pin 23a isseated within the bore 21a. The follower pin 23a includes an innersection 23b, an. outer section 23c, and a weakened or frangible neckconnecting portion 23d.

In addition, the outer section 230 is provided with a mushroom like headportion 23c of a diameter substantially conforming with the enlargedportion 21b of the bore 21a.

The casing 11 is provided with an opening 31, opening into the main bore12 and preferably positioned to register with the bore 21a in the lockedposition of the plug. The opening 31 is of a size which will permit theinner portion 23b of follower pin 23 to pass therethrough, the size ofsaid opening31 being smaller than the head portion 23e, however. As seenin FIGURES 1 and 4, driver spring 24a in the locked position of the plugis effective to force the head portion 23c of the follower pin 23aagainst the shoulder 210 formed in the cross bore 21a.

As shown in FIGURE 2, a temporary key K1, having a bitted upper face B1,has been inserted into the keyway 19 of the plug 11. While the entirebitted face of key K1 has not been shown, it should be understood thatsaid face is provided in the usual manner with a predetermined bittingsuitable to raise the follower pins 23 to a point whereat theiroutermostends lie precisely on the shear line A--A, and thereby presentno obstacle to theturning of the plug 11 within the cylinder 10.

The bitting B1 of the key K1 is likewise effective when engaged with thelower section 23!) of follower pin 23a to raise the outermost'end of theauxiliary driver pin 22b to the parting or shear line A A, therebyenabling the plug 11 to be turned within the .casing 10, bringing theeccentric actuator finger '32 carried by the plug 11 into trippingcontact with any known suitable locking mechanism.

The combination of the pin tumbler assembly is changed by actuating saidassembly with-a special change or master key K2 (see FIGURE 3). In theinserted position of key K2, the land or troughTZ of said ,key, whichisof a greater height than-the tropgh {T1 of key K1, serves to lift thefollower pin ZSasufliQientlY toposition the weakened neck portion 2312at the shear line A--A. The key K2 is then forcibly rotated in -the;plug11, causing the lower portion 23b of follower pin 23a to becomeseparated from the upper portion 23c thereof, by fracturing the followerpin at the nec k portion 2311. Under these circumstances, the lowerportion 23a will be retained within the plug, and the upper portion 230will be shifted to the bore 20a in the casing. ,As the plug 11 is turnedby key K2, the widened portion 21b of bore 21 is brought into registrywithopening 31in the casing 10, and the separated lowerpart 23b, at suchregistering position, may fall through the passage .31. If the lower orinner section 23a does not fall through open.- ing 31, as the plug isrotated to unlock the :door mechanism, this part will, as shown inFIGURE ,4, fall through said opening when the key K2 is withdrawn afterthe plug has been returned to the locked position thereof, since theopening 31 is optionally but preferably, positioned in the casing 10 toregister with cross .bore 21a when the plug is in said locked position.

It will be readily recognized that opening *31 need not be aligned withthe bore 21a in the locked position of the plug so long as said openingis positioned to register with the upper end 21b of said bore duringsome rotated position of the plug 11.

It will be further recognized that the opening 31 is desirably locatedat a point beneath the axis of the main bore 12 so that the innersection 23b will be induced to pass through said opening under theinfluence of gravity, At any rate, after the key K2 has been withdrawn,the combination of the tumbler assembly has been effectively changed byreason of the removal of the section 23b.

As shown in FIGURE 5, theowneris key K3 is bitted at its upper edge B3,and provided with a trough T3, which registers in the inserted positionof the key K3 with the cross bore 21a. The trough T3 of key K3 is of aheight calculated to raise the junction of follower pins 22a and 22b tothe parting or shear line AA when the lower face of the outer followerpin section 23a is seated in said trough. Further, the comparison ofFIG- URES 2 and will indicate that after the section 23b has beenremoved from the follower pin 23a, the construction or temporary key ,Klwill be ineffective to align the pins 4 in the bores 20a, 21a, with theshear line A-A, and thus will no longer be capable of operating thelock.

In the illustrated embodiment, the key K2 may serve as a master key tooperate the lock even after the combination has been changed todeactivate the temporary or construction key K1. To permit the key K2 toserve the function of a master after a combination change has beeneffected, the weakened neck portion 23;! is located precisely at thecenter point of the follower pin 23a. Under these circumstances thetrough T2 of the key K2 will be effective to lift the outer end of theouter section 230 of the follower pin precisely to the shear line AA,thus permitting the plug to be rotated in the casing. it will be readilyrecognized that'while the cross bores 20a, 21a are illustrated in thethird position of a five pin tumbler unit, this positioning may bevaried to provide additional security.

Likewise, while the cylinder plug device has been illustrated inconnection with a pair of driver pins 22a, 22b in the change bore, itwillbe readily recognized that if no mastering is desired, a singledriver pin in the change bore may be employed. In such instance, theneck or fracture point of the follower pin should be positionedotherwise than at the center of such pin, and the change key K2, aftereffecting the removal of the inner follower pin section,willthereafterbe ineffective to operate-the lock mechanism since theremaining follower pin section will not be raised by the key K2 to theshear line AA. in such instance, the owners key will be bitted to raisethe outer end of the outer follower pin section to the parting line.While the mastering through the use of following pins having a mediallylocated fracture point has been suggested, it will be readily recognizedthat conventional mastering and the grand mastering methods utilizing aplurality of driver pins may be resorted to where desired.

The above described device will be found highly useful in theconstruction of hotels, office buildings, apartments, developments andthe like, as providing a simplified system for changing the lockcombination after construction is completed. The great advantage in theuse of the invention herein described lies in the fact that thecombination changing key will not be effective to operate the lockmechanism where the follower pin has not beenfractured'at a-centralpoint. Thus, a maximum of security is assured.

By my invention .1 have provided a method of quickly and simply changingthe pin length of one or more pins to change the pin tumbler combinationof a lock in its mounting by the simple expedient of shearing thefrangible neckof the mushroom like auxiliary pm at a predeterminedfrangible point and disposing of the sheared oif section withoutdetection. Thus by aligning the boring 31 with theope-ning in a hollowdoor or within the shell of a door knob, whichever the pin tumblerassembly lock is mounted in, an inner tumbler section may beremoved,vpredeterminedly to change the key combination to provide the desiredsecurity from a temporary key to another key and without removing thelock from its mounting.

Having thus described the invention and illustrated its use, what isclaimed as new and is desired to be secured by Letters Patent is:

1. in a pin tumbler mechanism, a casing having a main bore, a plugrotatably mounted in said bore, a radially extending cross bore in saidcasing communicating with said main bore, a radial passage formedthrough said plug in alignment with said cross bore, a keyway formed insaid plug intersecting the longitudinal axis of said passage, afrangible follower pin reciprocablein said passage, said pin includinginner and outer sections separated by a weakened neck portion, a driverpin reciprocable in said cross bore, spring means in said casing urgingsaid driver pin against said outer section of said follower pin normallyto project said driver pin partly into said passage, an opening in saidcasing angularly offset from said cross bore and positioned to registerwith said passage in at least one' rotated position of said plug, saidopening being of a size to permit passage thereinto of said inner butnot said outer section of said follower pin, first key means bitted toraise the outer end of said outer section to the periphery of said plugwhen engaged with the inner end of said inner section, second key meansbitted to raise said neck to the periphery of said plug when engagedwith the inner end of said inner section, and third key means bitted toraise the outer end of said outer section to the periphery of said plugwhen engaged with the inner end of said outer section.

2. In a pin tumbler mechanism, a casing having a main bore, a plugrotatably mounted in said bore, a radially extending cross bore in saidcasing communicating with said main bore, a radial passage formedthrough said plug in alignment with said cross bore, a keyway formed insaid plug intersecting the longitudinal axis of said passage, afrangible follower pin reciprocable in said passage, said pin includinginner and outer sections separated by a weakened neck portion, blockingmeans on said outer section of said follower pin engaging said plug tolimit movement of said pin into said passage, a driver pin reciprocablein said cross bore, spring means in said casing urging said driver pinagainst said outer section of said follower pin normally to project saiddriver pin partly into said passage, an opening in said casing angularlyoffset from said cross bore and positioned to register with said passagein at least one rotated position of said plug, said opening being of asize to permit passage thereinto of said inner section but not saidblocking means, first key means bitted to raise the outer end of saidouter section to the periphery of said plug when engaged with the innerend of said inner section, second key means bitted to raise said neck tothe periphery of said plug when engaged with the inner end of said innersection, and third key means bitted to raise the outer end of said outersection to the periphery of said plug when engaged with the inner end ofsaid outer section.

3. In a pin tumbler mechanism, a casing having a main bore, a plugrotatably mounted in said bore, a radially extending cross bore in saidcasing communicating with said main bore, a radial passage formedthrough said plug in alignment with said cross bore, a keyway formed insaid plug intersecting the longitudinal axis of said passage, afrangible follower pin reciprocable in said passage, said pin includinginner and outer sections separated by a weakened neck portion, a head onsaid outer section of said follower pin, a driver pin reciprocable insaid cross bore, spring means in said casing urging said driver pinagainst said outer section of said follower pin normally to project saiddriver pin partly into said passage, an opening in said casingpositioned to register with said passage in at least one rotatedposition of said plug, said opening being of a size to permit passagethereinto of said inner section but not said head, first key meansbitted to raise the outer end of said outer section to the periphery ofsaid plug when engaged with the inner end of said inner section, secondkey means bitted to raise said neck to the periphery of said plug whenengaged with the inner end of said outer section, and third key meansbitted to raise the outer end of said outer section to the periphery ofsaid plug when engaged with the inner end of said outer section.

4. In a pin tumbler mechanism, a casing having a main bore, a plugrotatably mounted in said bore, a radially extending cross bore in saidcasing communicating with said main bore, a radial passage formed insaid plug rotatable into alignment with said cross bore, a keyway insaid plug intersecting said passage, a frangible follower pinreciprocable in said passage, said pin including inner and outersections separated by a weakened neck portion, a driver pin reciprocablein said cross bore, spring means in said casing urging said driver pinagainst said outer section of said follower pin normally to project saiddriver pin partly into said passage said outer section including meansthereon limiting movement of said outer section into said passage, anopening in said casing communicating with said main bore at a pointbeneath the axis of said main bore positioned to register with saidpassage in at least one rotated position of said plug, said openingbeing of a size to receive said inner section of said follower pin.

5. In a pin tumbler mechanism, a casing having a main bore, a plugrotatably mounted in said bore, a radially extending cross bore in saidcasing communicating with said main bore, a driver pin reciprocable insaid cross bore, a radial passage formed through said plug in alignmentwith said cross bore, a keyway formed in said plug intersecting thelongitudinal axis of said passage, a frangible follower pin reciprocablein said passage, said pin including inner and outer sections separatedby a weakened neck portion, an auxiliary driver pin interposed betweensaid driver and follower pins, spring means in said casing urging saiddriver pin against said auxiliary driver pin normally to project saiddriver pin partly and said auxiliary driver and follower pins fully intosaid passage, an opening in said casing angularly offset from said crossbore and positioned to register with said passage in at least onerotated position of said plug, said opening being of a size to permitpassage thereinto of said inner but not said outer section of saidfollower pin, first key means bitted to raise an end of said auxiliarydriver pin to the periphery of said plug when engaged with the inner endof said inner section, second key means bitted to raise said neck to theperiphery of said plug when engaged with the inner end of said innersection, and other key means bitted to raise an end of said auxiliarydriver pin to the periphery of said plug when engaged with the inner endof said outer section.

6. A pin tumbler mechanism in accordance with claim 1 wherein saidpassage includes an enlarged portion adjacent the periphery of said plugand a constricted portion, and said driver pin is of a size to entersaid enlarged portion but not said constricted portion.

7. A device in accordance with claim 5 wherein said inner and outersections of said follower pin are of equal length.

References Cited in the file of this patent UNITED STATES PATENTS1,650,564 Wolfi Nov. 22, 1927 1,650,568 Hurd Nov. 22, 1927 2,007,143Keil July 2, 1935 2,059,129 Maxwell et a1. Oct. 27, 1936 2,591,652Ziegliss Apr. 1, 1952 UNITED sTATEs PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3,073,146 January 15, 1963 George P. Patriquin Itis hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

In the sheet of drawings, in Figures 1 to 5, a reference numeral "20a"should identify the cross bores in casing 10 within which the pin 22a isdisposed; that, in Figure 1, the lead line from reference numeral 20should extend within the cross bore in the casing 10 within which thefollower pin 22 is disposed; and that, in Figure 5, a legend "T3" shouldidentify the trough on the upper edge B3 of key K3 directly beneathouter follower pin section 230; column 2, line 32, for "21", firstoccurrence, read 2O line 54, for "23h" read 22b same column 2, line 71,for "11" read 1O column 3, line 33, for "2310" read 23d line 37, for"23a" read 23d. line's 38 and 45, for "23a", each occurrence, read 23bsame column 3, line 71, for "23a read 23c Signed and sealed this 19thday of November 1963,

(SEAL) Attest: EDWIN L, REYNOLDS ERNEST W. SWIDER Attesting Officer Acting Commissioner of Patents

4. IN A PIN TUMBLER MECHANISM, A CASING HAVING A MAIN BORE, A PLUGROTATABLY MOUNTED IN SAID BORE, A RADIALLY EXTENDING CROSS BORE IN SAIDCASING COMMUNICATING WITH SAID MAIN BORE, A RADIAL PASSAGE FORMED INSAID PLUG ROTATABLE INTO ALIGNMENT WITH SAID CROSS BORE, A KEYWAY INSAID PLUG INTERSECTING SAID PASSAGE, A FRANGIBLE FOLLOWER PINRECIPROCABLE IN SAID PASSAGE, SAID PIN INCLUDING INNER AND OUTERSECTIONS SEPARATED BY A WEAKENED NECK PORTION, A DRIVER PIN RECIPROCABLEIN SAID CROSS BORE, SPRING MEANS IN SAID CASING URGING SAID DRIVER PINAGAINST SAID OUTER SECTION OF SAID FOLLOWER PIN NORMALLY TO PROJECT SAIDDRIVER PIN PARTLY INTO SAID PASSAGE SAID OUTER SECTION INCLUDING MEANSTHEREON LIMITING MOVEMENT OF SAID OUTER SECTION INTO SAID PASSAGE, ANOPENING IN SAID CASING COMMUNICATING WITH SAID MAIN BORE AT A POINTBENEATH THE AXIS OF SAID MAIN BORE POSITIONED TO REGISTER WITH SAIDPASSAGE IN AT LEAST ONE ROTATED POSITION OF SAID PLUG, SAID OPENINGBEING OF A SIZE TO RECEIVE SAID INNER SECTION OF SAID FOLLOWER PIN.